无法覆盖 FastAPI/FastAPi-Utils 中的依赖项答案

【问题标题】：Unable to override dependency in FastAPI/FastAPi-Utils无法覆盖 FastAPI/FastAPi-Utils 中的依赖项
【发布时间】：2020-10-21 15:24:17
【问题描述】：

这可能是一个新手问题。我无法覆盖这个简单的 2 个文件 FastAPI 项目中的问候消息。你能告诉我我可能做错了什么吗？非常感谢您的帮助。

greetings_service.py

from fastapi import Depends
from fastapi_utils.cbv import cbv
from fastapi_utils.inferring_router import InferringRouter


router = InferringRouter()

def get_msg():
    return "Original Message"

@cbv(router)
class GreetingsService:
    @router.get("/")
    async def greet(self, msg: str = Depends(get_msg)):
        return f"Hello from FastAPI {msg}"

main.py

from fastapi import FastAPI
from starlette.testclient import TestClient

import greetings_service

app = FastAPI()
app.include_router(greetings_service.router)

def get_new_msg():
    return "New Message"

//Tried this, doesn't work
#app.dependency_overrides["get_msg"] = get_new_msg()

//These 2 lines doesn't work too
app.dependency_overrides["get_msg"] = get_new_msg()
greetings_service.router.dependency_overrides_provider = app

client = TestClient(app)

res = client.get("/")
print(res.content) #"Hello from FastAPI Original Message" :(

【问题讨论】：

标签： python fastapi

【解决方案1】：

问题在于：

app.dependency_overrides["get_msg"] = get_new_msg()

您将依赖项作为字符串而不是实际依赖项传递。

这样的事情会起作用：

from fastapi import FastAPI
from starlette.testclient import TestClient

import greetings_service

app = FastAPI()
app.include_router(greetings_service.router)


def get_new_msg():
    return "New Message"


app.dependency_overrides[greetings_service.get_msg] = get_new_msg

client = TestClient(app)
res = client.get("/")
print(res.content)

【讨论】：